Feeding mechanisms for sewing machines



Nov. 22, 1955 A. J. MATUZAS FEEDING MECHANISMS FOR SEWING MACHINES FiledJan. 15, 1954 IN VEN TOR. Anfh ony J. Moruzos A TTORNEY 2,724,354Patented Nov. 22, 1955 United States Patent Ofifice 2,724,354 FEEDINGMECHANISMS FOR SEWING MACHINES Anthony J. Matuzas, Union, N. 1.,assignor to The Singer Manufacturing Company, Elizabeth, N. J., acorporation of New Jersey Application January 15, 1954, Serial No.404,300

7 Claims. (Cl. 112-210) :This invention relates to sewing machines andmore particularly to improvements in feed-dog throw-out devicesespecially adapted foruse with family-type sewing machines. Feed-dogthrow-out devices are designed to inactivate the work-feeding mechanismof sewing machlnes when it is desired to use the machine for darning,

embroider-ing and other similar operations, and to reactivate thefeeding mechanism when the machine is to be used for ordinary sewingoperations.

The present invention is applicable to the feed-dog throw-out devicewhich is described in the prior patent applications Serial No. 222,616,filed April 24, 1951, now Patent No. 2,682,242, and Serial No. 301,644,filed July 30, 1952, now Patent No. 2,682,243, and the present inventionhas for its primaryobject the provision of an improved feed-dogthrow-out device.

Another object of the invention is to provide an improved feed-dogthrow-out device which is quicker and easier to operate and morepositive in its action than similar devices heretofore used.

With the above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations, and arrangements ofparts hereinafter set forth and illustrated in the accompanying drawingsof a pre' ferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art. i

In the accompanying drawings: s

Fig. 1 is a vertical sectional view of a portion of a sewing machinewith a feed-dog throw-out device embodying the present invention,

Fig. 2 is a bottom plan view of the portion of the sewing machine shownin Fig. 1, and

i Fig. 3 is an exploded perspective view of certain of the elementsillustrated in Figs. 1 and 2.

In the embodiment of this invention selected for illustration, numeral11 indicates a substantially rectangular bed-plate or base of a sewingmachine, providing on its upper side a work-carrying plate 12 formed onits under side with depending front and rear walls 14 and 16, and endwalls 17 and 18, forming a box-like enclosure, of which the downwardlyfacing opening is normally closed by a bottom cover-plate 19 held by anut (not shown). 7 An upstanding hollow standard 21 rises from the bed11 and at its upper end the standard carries an overhanging upper arm(not shown) in the free end of which are arranged the usualreciprocatory needle-bar 24 and the resser-bar 25.

Journaled in the upper arm (not shown) is a main driveshaft (not shown),which operates the needle-bar 24, in a known manner, and this samedrive-shaft in a manner shown and described in Patent No. 2,617,375drives a loop-taker shaft 27, which in turn drives a looptaker 28arranged to cooperate with a thread-carrying needle 29 in the formationof stitches. Since the stitchforming mechanism forms no part of thepresent invention, further illustration and description thereof isdeemed unnecessary.

The work-carrying plate 12 is provided with a throatplate 31 havingfeed-slots 32 through which operates a serrated feed-dog 34 secured byscrews 37 on one end of a long feed-bar 36. At its rearward end, thefeed-bar 36 is pivotally connected, at 38, to the upper end of a pair offeed-advance rockers 39 extending upwardly from a feed-advancerock-shaft 41 journaled on pintles of which one is shown at 42. Also afeed-lift rock-shaft 44 is journaled on pintles, of which one is shownat 43. Oscillatory movements are given to the feed-advance rockshaft 41and the feed-lift rock-shaft 44 by any known means such, for example, asdescribed :in Patent No. 2,617,375.

The feed-bar 36 is provided with a depending lug 47, of which the lowerend carries a horizontally extending pin 48 that pivotally mounts thelower end of an upwardly extending link 49. The upper end of the link49is pivotally connected by a pin 51 to one arm 52 of a horizontallyextending lever 53 having a central hub 54 freely journaled on thefeed-lift rock-shaft 44. The hub 54 is provided with an annular recess56 coaxial with the shaft 44. The recess 56 accommodates a. helicalspring 57 one end of which is anchored in a hole 58 formed in the lever53 and the other end is anchored in a hole 59 provided in a flange 61integral with the feed-lift rockshaft 44. The lever 53 is held frommovement in the other direction longitudinally of the shaft 44 by aspring wire clip 62 seated in a groove in the shaft 44. Another arm 63of the horizontally extending two-armed lever 53 is apertured by ahorizontally extending funnel-shaped hole or clearance aperture having acylindrical portion 64 and having, at its end nearest the wall 17 andthus remote from the crank-arm 68 hereinafter mentioned, a concavefrusto-conical countersink or seat portion 66for seating a convexfrusto-conical self-centering member 221, presently to be described.

. It will be noted that the two arms 52 and 63 of the lever 53 extendhorizontally on opposite sides of the feedlift rock-shaft 44, the arm 52extending toward the loop: taker shaft 27 in the front of the sewingmachine bed, and the arm 63 extending toward the feed-advance rock-shaft41 in the rear of the bed. It will also be noted that the lever 53 is ofuniform thickness as measured in the direction of the axis of thefeed-lift rock-shaft 44. Also the seating members 66 and 221 are both ofsymmetrical, frusto-conical form, and the cylindrical portion 64 and thefrusto-conical portion 66 are coaxial.

The hereinbefore mentioned feed-lift rock-shaft 44 carries ahorizontally extending crank-arm 68 adjacent to and integral with theflange 61. In order to limit the downward movement of the feed-dog 34,.there is provided a bracket 83, which is held by a screw 82 to a bossformed on the base 11. The bracket 83 has a threaded hole and therebycarries an adjustable stop screw 86 of which the upper end (not shown)may be engaged by the lower surface of the arm 52. The previouslydescribed mechanism is substantially the same as the mechanism whichformed the subject of patent application Serial No. 222,616 supra.

The present invention is concerned primarily with improved means forselectively connecting and disconnecting the integrally formed flange 61and the crank-arm 68 with the arm 63 which is apertured by the hole 6466of which, as stated, one portion 64 is cylindrical and the other portion66 is frusto-conical. This connecting means comprises a cylindrical stemor screw 201. of which one end is threaded as at 202, the thread end 202of the stem,

201 being screwed into a threaded hole 203formed in the arm 68, and anut 204 locks the end 202 of the stem 201 to the arm 68 which arm isformed integral with the feed-lift rock-shaft 44. The unthreaded or freeend of the tem Wines an nlar gnt r a y in a h ad 205 having a hole 206that carries a radially disposed cam-pin 207 and turnably mounted on thehead 205 is a hollow cylindrical sleeve 208, equipped with an operatinghandle 209 which extends radially from the outer end of the sleeve208.The cylindrical wall 211 of the hollow sleeve 208 .is provided with aspiral cam-slot 212 one end of which terminates in an enlarged notch orpositioning recess 213. When the parts are assembled, the pin 207 entersthe cam slot 212 or the recess 213 and operates in a manner-later to bedescribed. As best seen in Fig. 2, a comparatively strong helicalcompression spring 214 surrounds the stem 201, one end of the spring 214engaging one end of the hollow sleeve 208 and the other end ofithespring 214 engaging the smaller end of a hollow sleeve-member 216 havingan enlarged end or head 217 and a cylindrical stem 218 provided with anunthreaded concentric bore 219 extending the full length of the stem21,8 and the head 217. The enlarged end 217 has an outfacing convexfrusto-conical member or centering surface 221 having the same conicityas the concave frustoconical countersink 66 hereinbefore described. Theconvergent endof the member 221 engages one end of a relatively weakhelical compression spring 222 and the other end .of the weaker spring222 is seated in a recess 22,3 coaxially formed with respect to thethreaded hole 203 ,inthe flanged crank arm 68.

In operation, the device functions in the following manner. If it'isassumed that the feed-dog 34 is raised so that the sewing machine mayperform ordinary straightaway stitching operations, the handle 209 willbe turned to the position shown by solid lines in Fig. 1, and the .pin207 .will be positioned in the recess 213. This causes the sleeve 208.to compress the spring 214 which moves the sleeve member 216 along thestem 201 until the frustoconical centering surface 221 is pressed firmlyagainst the inner surface of the countersink 66. Since the spring 222 isrelatively weaker than the spring 214, the weaker spring 222 will becompressed fully and thus will allow the" surface 221 to seat in thecountersink 66.

If it is desired to use the sewing machine for darning or'embroidering,in which case the feed-dog must be lowered to an ineffective positionbelow the top surface of the throat-plate, the handle 209 will be turnedcounterclockwise to the dotted position shown in Fig. 1. Turning thehandle 209 and thus the sleeve 208 first causes the pin 207 to becomedisengaged from the recess 213 and then to move along the slot 212to theend 212. When this happens the strong spring 214 is relaxed sufficientlyso that the weak spring moves the member 216 to the left in Fig. 2,thereby disengaging the surface 221 from the seat 66 with the resultthat the coil-spring 57 turns the double armed lever 53 clockwise(Fig. 1) about the shaft 44 to" lower the feed-dog 34 in a mannersimilar to that described in patent applications Serial Nos. 222,616 and301,644, supra. When it is desired to return the feed-dog to its properelevated work-feeding position, it is only necessary to turn the handle209 in a clockwise direction, asviewed in Fig. 1. This causes the sleevemember 208 to move endwise inwardly of the stem 201, thereby compressingthe strong spring 214 which forces the member 216 with itsfrusto-conical centering surface 221 toward and into the aperture 66 ofthe arm 63. When the member 216 is fully seated in the aperture 66 thefeeddog is elevated to its proper height for work-feeding operation. h i

Having thus set forth the nature of the invention, what I claim hereinis: V

1. A'feeding mechanism for sewing machines comprising a feed-dog, afeed-advance rock-shaft'connectedto said feed-dog forimpartingfeed-advance motion thereto, a.fed-liftfrok-shaft, anddisengageable connecting means interposed between said feed-liftrock-shaft and said feeddogysaid disengageabl'e connecting meanscomprising a first member operated by said feed-lift rock-shaft, asecond m m e onne d o ai f ed-d e a o b d ice carried by one of saidmembers and movable into engagement with said other member, a springengaging one end of said movable device, and means for compressing saidspring thereby moving said movable device and connecting said movabledevice with said other member.

2. A feeding mechanism for sewing machines comprising a feed-dog, afeed-advance rock-shaft connected to said feed-dog for impartingfeed-advance motion thereto, a feed-lift rock-shaft, and disengageableconnecting means interposed between said feed-lift rockshaft and saidfeed-dog; said disengageableconnecting means comprising a first memberoperated by said feedlift rock-shaft, a second member-connected to saidfeeddog, a movable device carried by one'of said members and movableinto engagement with said other member, a comparatively weak springlocated between one of said members and one end of said movable device,a comparatiyely strong spring engaging the other end of said movabledevice, and means for compressing said strong spring thereby moving saidmovable device, compressing said weak spring, and connecting saidmovable device with said other member.

'3. A feed-dog throw-out mechanism for sewing machines including incombination, a rock-shaft, a crankarm secured to said rock-shaft andsaid crank-arm being provided with a hole, a lever pivoted on saidrock-shaft and provided with a hole, one of said holes being frustoconical, a feed -dog, means connecting said lever with said feed-dog, areleasable connection selectively connecting and disconnecting saidlever and said crank-arm, said releasable connection comprising, a sternmember freely passing through said frusto-conical hole and entering saidother hole, means for locking said stem member into said other hole, ahollow cylindrical sleeve memberturnably monnted on said stem member,one of said members being provided with a spiral cam groove and theother of said members being provided with a cam-pin cooperating withsaid cam groove, and a sleeve member slidably mounted on said stern andhaving a frusto-conical end adapted to enter said frnsto-conical hole.

4. A feed-dog throw-out mechanism for sewing machines including incombination, a rock-shaft, a crankarrn secured to said rock-shaft andsaid crank-arm being provided with a hole, a lever pivoted on saidrock-shaft and provided with a hole, one of said holes being threadedand the other of said holes being frusto-conical, a feeddog, meansconnecting said lever with said feed-dog, a'releasable connectionselectively connecting and disconnecting said lever and said crank-arm,said releasable connection comprising, a stem freely passing throughsaid frusto-conical hole and screwed into said threaded hole, means forlocking said stem into said threaded hole, an unthreaded cylindricalhead on the free end of said stem, a cam-pin protruding from said head,a hollow cylindrical sleeve turnably mounted on the head of said stemand said hollow sleeve being provided with a spiral cam slot c0-operatingwith said cam-pin, and a sleeve member slidahly mounted on saidstem and having a frusto-conical end adapted to enter saidfrusto-conical hole.

5. A feed-dog throw-out mechanism for sewing machines including incombination, a rock-shaft, a crankarm secured to said rock-shaft andsaid crank-arm being provided with a hole, a lever pivoted on saidrock-shaft and provided with a hole, one of said holes being threadedand the other of said holes being frusto-conical, a feeddog, meansconnecting said lever with said feed-dog, a releasable connectionselectively connecting and disconnecting said lever and said crank-arm,said releasable connection comprising, a stem freely passing throughsaid frns to-conica'l hole and screwed into said threaded hole, a nutlocking said stem into said threaded hole arm, an unthreaded cylindricalhead on the free end of said stein 5 and saidhead having a radial hole,acam-pin protruding from said radial hole, a hollow cylindrical sleeveturnably mounted on the head of said stem and said hollow sleeve beingprovided with a spiral cam slot cooperating with said cam-pin and saidcam slot having an enlarged positioning notch at one end thereof, asleeve member slidably mounted on said stem and having a frusto-conicalend adapted to enter said frusto-conical hole.

6. A feed-dog throw-out mechanism for sewing machines including incombination, a rock-shaft, a crankarm secured to said rock-shaft andsaid crank-arm being provided with a threaded hole, a lever pivoted onsaid rock-shaft and prOvided with a hole, one of said holes beingthreaded and the other hole being frusto-conical, a feed-dog, meansconnecting said lever with said feeddog, a releasable connectionselectively connecting and disconnecting said lever and said crank-arm,said releasable connection comprising, a stem freely passing throughsaid frusto-conical hole and screwed into said threaded hole of saidcrank-arm, a nut locking said stem into said threaded hole, anunthreaded cylindrical head on the free end of said stem and said headhaving a radial hole, a cam-pin protruding from said radial hole, ahollow cylindrical sleeve turnably mounted on the head of said stem andsaid hollow sleeve being provided with a spiral cam slot cooperatingwith said cam-pin and said cam slot having an enlarged positioning notchat one end thereof, a sleeve member slidably mounted on said stem andhaving a frusto-conical end adapted to enter said frusto-conical hole, acomparatively heavy helical spring surrounding said stern and positionedbetween the head of said stem and said sleeve member, and acomparatively weak spring surrounding said stem and positioned betweensaid sleeve member and said crank-arm, said weak spring being of suchsize as to pass freely through said frusto-conical hole.

7. A feed-dog throw-out mechanism for sewing machines including incombination, a rock-shaft, a crankarm formed integral with saidrock-shaft and said crankarm being provided with a threaded hole and aspring receiving hole coaxial therewith, a lever pivoted on saidrock-shaft and provided with a funnel-shaped hole having a cylindricalportion and a frusto-conical portion coaxial with said cylindricalportion, a feed-dog, means connecting said lever with said feed-dog, areleasable connection selectively connecting and disconnecting saidlever and said crank-arm, said releasable connection comprising, a stemfreely passing through said funnel-shaped hole and screwed into saidthreaded hole of said crank-arm, a nut locking said stem to saidcrank-arm, an unthreaded cylindrical head on the free end of said stemand said head having a radial hole, a cam-pin protruding from saidradial hole, a hollow cylindrical sleeve turnably mounted on the head ofsaid stem and said hollow sleeve being provided with a spiral cam slotcooperating with said cam-pin and said cam slot having an enlargedpositioning notch at one end thereof, a sleeve member slidably mountedon said stem and having a frusto-conical end adapted to enter saidfrusto-conical portion of said funnel-shaped hole, a comparatively heavyhelical spring surrounding said stem and positioned between the head ofsaid stem and said sleeve member, and a comparatively weak springsurrounding said stern and positioned between said sleeve member andsaid crank-arm, said weak spring being of such size as to pass freelythrough the cylindrical portion of said funnel-shaped hole and to enterthe spring receiving hole in said crank-arm.

References Cited in the file of this patent UNITED STATES PATENTS2,440,031 Wainwright Apr. 20, 1948 2,643,625 Reimer June 30, 19532,682,243 Matuzas June 29, 1954

